Fossil Corals Shed Light on Future of Melting Polar Ice Sheets

Fossil corals found on islands in the Indian Ocean are shedding light on the future of melting polar ice sheets, an important revelation considering current climate change, according to a new study.

About 125,000 years ago, the average global temperature was only slightly warmer than it is today. However, these high temperatures still managed to raise the global mean sea level up to a staggering 20 to 30 feet above current levels. This submerged the locations of many of today's coastal cities, and paints a worrisome picture of future sea level rise.

"Following a rapid transition to high sea levels when the last interglacial period began, sea level continued rising steadily," University of Florida geochemist Andrea Dutton, who led the study, said a statement. "The collapse of Antarctic ice occurred when the polar regions were a few degrees warmer than they are now - temperatures that we are likely to reach within a matter of decades."

While sea level rise in the Last Interglacial period was driven by the same processes that we see today - including thermal expansion of seawater, melting mountain glaciers, and melting polar ice sheets in Greenland and Antarctica - it was polar ice sheet melt that caused the most drastic changes.

It seems strange that fossil corals from the tropical islands of Seychelles, in the Indian Ocean, could reveal much about the fate of frigid polar ice sheets. But indeed they did show not only the damage that melting ice sheets can cause worldwide during the Last Interglacial period, but that we may experience similar repercussions in the distant future as a result of climate change.

What's more, "We could be poised for another partial collapse of the Antarctic ice sheet," Dutton added.